1. Field of the Invention
The present invention relates to an improved ceramic heater and a process for producing the same. The ceramic heater of the present invention has a heat-generating body composed of a sintered body which comprises, as the main ingredients, an electroconductive ceramic and an insulating material such as silicon nitride.
2. Description of the Prior Art
The use of metals and ceramics in the manufacture of heat-generating bodies is known in the art. Examples of metals which have been used in the manufacture of metal heat-generating bodies include nichrome, kanthal and the like. These materials, however, are poor in heat resistivity. Examples of ceramics which have been used in the manufacture of ceramic heat-generating bodies include silicon carbide, molybdenum disilicite, lanthanum chromate (LaCrO.sub.3) and the like. However, the thermal shock resistivity and strength of these materials are insufficient. In addition, due to the high specific resistance of these materials, it is difficult to use them at a low voltage; for example, a voltage of 12 V, which is available from a car battery.